1. Field of the Invention
The present invention relates to a built-in retractable flash of a camera.
2. Description of the Related Art
Cameras having a pop-up electronic flash in which a light emitter rises from an accommodation position to an emission position are well-known. In a known pop-up device for a built-in electronic flash, the light emitter is supported at its opposite ends by a pair of pop-up arms whose ends are pivotally connected to a camera body. In a known lock (engagement/disengagement) apparatus which locks the light emitter in the accommodation position (retracted position) and unlocks the light emitter, engagement levers (lock levers) and disengagement levers (unlocking levers) or springs which move the engagement levers in the disengagement direction are provided on a common shaft. Such a lock apparatus is reliable since there are little spring force losses.
For instance, the disengagement levers are each held by an armature of an electromagnetic plunger in an inoperative position, in which the disengagement lever does not act on the engagement lever when the built-in retractable flash is in the accommodation position. When the electromagnetic lunger is energized, the armature is released, so that the engagement lever is rotated into the disengagement direction to release the engagement. The electromagnetic plunger is secured to a support plate to which the engagement lever and the disengagement lever are secured, to form a single unit. The unit is secured to an immovable portion of the camera body by screws.
However, if the engagement lever, the disengagement lever, and the electromagnetic plunger are integrally formed as a unit, it is impossible to adjust a relative angle or position between the electromagnetic plunger and the disengagement lever. To this end, the electromagnetic plunger is not secured to the unit, so that the adjustment can be carried out, using a jig which holds the electromagnetic plunger as if the latter was secured to the unit. Namely, it is necessary to use the jig for the adjustment. Also, once the unit is mounted to the camera, no adjustment can be carried out.
Furthermore, since the two levers and the two springs are provided on the same shaft in the conventional built-in retractable flash, as mentioned above, the width of the flash (i.e., the axial direction of the shaft) is increased, so that a large space in the lateral direction of the camera is necessary for the built-in flash. Consequently, the width of the accommodation portion in which the light emitter and the support mechanism therefor are received is increased. Therefore, if an operation dial is provided aside the accommodation portion, the diameter of the dial or the distance between the dial and the accommodation portion is restricted.
It is an object of the present invention to provide a built-in retractable flash which can be easily assembled and adjusted and which has a sufficient strength.
Another object of the present invention is to provide a built-in retractable flash in which the width thereof can be reduced, so that an accommodation space in which the light emitter and the support mechanism are accommodated can be made small.
To achieve the object mentioned above, according to an aspect of the present invention, a built-in retractable flash of a camera is provided, including a light emitter which is supported on a camera body to be movable between a retracted position and a light emission position raised from the camera body; a lock lever mechanism having a lock lever which is movable between a lock position, wherein the lock lever engages with the light emitter to hold the light emitter in the retracted position, and an unlock position, wherein the lock lever allows the light emitter to move to the light emission position, the lock lever being biased toward the lock position; a base plate of the lock lever mechanism on which the lock lever is supported; an electromagnetic member provided on the base plate, the electromagnetic member being adapted to control the position of the lock lever between the lock position and the unlock position; a position adjustment mechanism for adjusting the position of the electromagnetic member on the base plate; and, a first and a second securing device for securing the base plate to the camera body; wherein the first securing device secures only the base plate to the camera body; and wherein the second securing device secures both the base plate and the electromagnetic member to the camera body after the relative position between the base plate and the electromagnetic member is adjusted by the position adjustment mechanism.
With this arrangement, the adjustment of the relative position and/or direction of the electromagnetic member and the lock lever mechanism can be facilitated and can be carried out even after the built-in flash is attached to the camera.
The position adjustment mechanism can be provided with a positioning pin and a positioning hole in which the positioning pin is fitted, which are formed on one and the other of the base plate and the electromagnetic member, wherein the electromagnetic member is rotatable with respect to the base plate about the center axis of the positioning pin.
The first securing device can be provided with a first positioning projection formed on the camera body; a first threaded hole formed in the first positioning projection; a first through hole formed on the base plate, in which the first positioning projection of the camera body can be inserted; and a first screw which is engaged with the threaded hole in the first through hole and secures the base plate to the positioning projection.
The second securing device can be provided with a second positioning projection formed on the camera body; a second threaded hole formed in the second positioning projection; a second through hole formed on the base plate, in which the second positioning projection of the camera body can be inserted; a third through hole formed on the electromagnetic member in which the second positioning projection of camera body can be inserted; a second screw which can be engaged with the second threaded hole through the second and third through holes and secures the electromagnetic member to the second positioning projection together with the base plate.
Preferably, the first and second positioning projections of the camera body are fitted into the first and second through holes of the base plate, respectively, so as to have a predetermined amount of slack in a direction perpendicular to the axes of the first and second screws, so that the position of the base plate is adjustable with respect to the camera body when the first and second screws are loosened.
Preferably, the camera body includes an outer plate secured to the camera body, the first and second positioning projections being formed on the inner surface of the outer plate.
In an embodiment, the lock lever mechanism further includes an unlocking lever which is supported on the base plate so as to be moved between a lock-allowing position, which allows the lock lever to be positioned in the lock position, and an unlocking-operation position, which moves the lock lever to the unlock position via the electromagnetic member; and a biasing member for biasing the unlocking lever to the unlocking-operation position, wherein a biasing force of the biasing member is stronger than a biasing force which biases the lock lever to the lock position.
In case that the lock lever mechanism is provided with the unlocking lever, it is preferable that the electromagnetic member includes an armature which is connected with the unlocking lever, a permanent magnet which attracts the armature, and a coil which produces a magnetic force which cancels the magnetic force of the permanent magnet when the coil is supplied with electricity. When the coil is not supplied with electricity, the armature is attracted by the permanent magnet so that the unlocking lever is held in the lock-allowing position wherein the lock lever is held in the lock position. When the coil is supplied with electricity, the unlocking lever is moved to the unlocking-operation position by the biasing force of the biasing member so that the armature is engaged with the lock lever and moves the lock lever to the unlock position.
According to another aspect of the present invention, a built-in retractable flash of a camera is provided, including a light emitter which is supported on a camera body to be movable between a retracted position and a light emission position raised from the camera body; a lock lever which is rotatable between a lock position, wherein the lock lever engages with the light emitter to hold the light emitter in the retracted position, and an unlock position, wherein the lock lever allows the light emitter to move to the light emission position, the lock lever being biased toward the lock position; a first biasing member for biasing the lock lever to the lock position; an unlocking lever which is rotatable between a lock-allowing position, which allows the lock lever to rotate to the lock position, and an unlocking-operation position, which rotates the lock lever to the unlock position a second biasing member for biasing the unlocking lever to the unlocking-operation position; a biasing force of the second biasing member being stronger than a biasing force of the first biasing member; and a base plate on which the lock lever and the unlocking lever are rotatably supported; an electromagnetic member which holds the unlocking lever in the lock-allowing position against the biasing force of the second biasing member. The electromagnetic member is secured to the camera body together with the base plate via a common securing screw.
In this built-in retractable flash, it is preferable that the base plate is provided with a positioning pin which can be fitted in a positioning hole formed in the electromagnetic member.
In an embodiment, the base plate is secured to a projection formed on the camera body together with the electromagnetic member via the common securing screw.
Preferably, the built-in retractable flash further includes a base plate securing projection formed on the camera body; and a base plate securing screw. The base plate securing screw secures only the base plate to the base plate securing projection of the camera body and the common securing screw secures both the base plate and the electromagnetic member to the projection (which differs from the base plate securing projection).
Preferably, the electromagnetic member includes an armature which is connected with the unlocking lever, a permanent magnet which attracts the armature, and a coil which produces a magnetic force which cancels the magnetic force of the permanent magnet when the coil is supplied with an electricity. The unlocking lever is held in the lock-allowing position when the armature is attracted by the permanent magnet so that the lock lever is positioned in the lock position by biasing force of the first biasing member. The unlocking lever is rotated to the unlocking-operation position by the biasing force of the second biasing member when the attracting force of the permanent magnet is canceled by the magnetic force of the coil, so that the lock lever rotates to the unlock position.
According to another aspect of the present invention, a built-in retractable flash of a camera is provided, including a light emitter which is supported on a camera body to be movable between a retracted position and a light emission position raised from the camera body; a lock lever which is rotatable between a lock position, wherein the lock lever engages with the light emitter so as to lock the light emitter in the retracted position, and an unlock position, wherein the lock lever disengages with the light emitter in order to allow the light emitter to move the light emission position; a first biasing member for biasing the lock lever to the lock position; an unlocking lever which is rotatable between a lock-allowing position, which allows the lock lever to be positioned in the lock position, and an unlocking-operation position, wherein the lock lever rotates to the unlock position; a second biasing member for biasing the unlocking lever to the unlocking-operation position, wherein a biasing force of the second biasing member is stronger than a biasing force of the first biasing member; first and second rotational shafts which rotatably support the lock lever and the unlocking lever respectively; and an electromagnetic member which holds the unlocking lever in the lock-allowing position when electricity is not supplied to the electromagnetic member, and releases the unlocking lever so as to rotate to the unlocking-operation position when electricity is supplied to the electromagnetic member. The first and second rotation shafts extend in parallel in a direction of the axes thereof, and are spaced from one another in a direction perpendicular to the axes.
With this structure, since the lock lever and the unlocking lever are not coaxial, the lateral width of the built-in flash can be reduced.
Preferably, the first rotation shaft of the lock lever and the second rotation shaft of the unlocking lever are spaced from one another in the forward and rearward direction of the camera body.
Preferably, the first biasing member is a torsion coiled spring which is wound about the first rotation shaft, and wherein the second biasing member is a torsion-coiled spring which is wound about the second rotation shaft.
The electromagnetic member can be provided with an armature which is connected with the unlocking lever, a permanent magnet which attracts the armature, and a coil which produces a magnetic force which cancels the magnetic force of the permanent magnet when the coil is supplied with electricity. When the coil is not supplied with electricity, the armature is attracted by the permanent magnet, and the unlocking lever is held in the lock-allowing position so that the lock lever is held in the lock position. When the coil is supplied with electricity, the unlocking lever is moved to the unlocking-operation position by biasing force of the second biasing member so that the armature is engaged with the lock lever and moves the lock lever to the unlock position.
Preferably, the built-in retractable flash further includes a charge member which compresses the second biasing member to thereby increase the elastic biasing force when the light emitter is in the retracted position, and which allows the second biasing member to expand to thereby allow the armature to be attracted by the permanent magnet when the light emitter is moved in the direction toward the light emission position.
Preferably, the built-in retractable flash further includes a third biasing member for biasing the light emitter to the light emission position.
Preferably, the camera is a single lens reflex camera and the light emitter is provided on a pentagonal roof of the single lens reflex camera.
Preferably, the first and second rotational shafts are provided on a common base plate.
The present disclosure relates to subject matter contained in Japanese Patent Applications Nos. 11-179748 (filed on Jun. 25, 1999) and 11-179749 (filed on Jun. 25, 1999) which are expressly incorporated herein by reference in their entireties.